生活本来就不容易,而我们的不努力只会让生活变得更加无赖
今天学习了如何利用FragmentTabHost以及ViewPager的知识点,简单写了个demo实现界面滑动点击切换的效果.现在市面上大部分的APP都有这种类似的功能,如微信,等等,相信实现方法略同.因此便写一篇日记记录该功能的实现.demo部分截图如下:
FragmentTabHost的用法(要点)
- Activity必须继承自FragmentActivity(AppCompatActivity为其子类).
- 使用setup()方法绑定Fragmenrt,
- 使用TabHost.TabSpec 设置spec,spec则需要indicator,indicator则需要View填充.
- 实现setOnTabChangedListener接口来对Viewpager的滑动进行监听
ViewPager的用法(要点)
1.Viewpager被添加在v4包当中,官方推荐结合Fragment使用以实现滑动切换的效果,因此需要一个适配器Adapter继承FragmentPagerAdapter装载Fragment.
2.实现addOnPageChangeListener接口来对FragmentTabHost的点击的监听.
由上可知,我们需要写几个xml文件显示相关::
- tabhost.xml
```
* 这里需要注意的地方是,在FragmentTabHost里面的FrameLayout的id必须为```@android:id/tabcontent```
* 给indicator填充的item_view.xml
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="10dp"
android:layout_marginBottom="10dp">
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:padding="3dp">
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="10sp"
android:layout_gravity="center"
android:textColor="@color/tab_text">
- fragment1.xml(这里需要四个,但全部相同,先贴出一个)
```
#### ViewPager的适配器以及监听接口的实现:
* MyAdapter.java
public class MyAdapter extends FragmentPagerAdapter{
private List
public MyAdapter(FragmentManager fm,List
super(fm);
this.views = list;
}
@Override
public Fragment getItem(int position) {
return views.get(position);
}
@Override
public int getCount() {
return views.size();
}
}```
- MyPageChangeListener.java
public class MyPageChangeListener implements ViewPager.OnPageChangeListener {
private FragmentTabHost tabHost;
public MyPageChangeListener(FragmentTabHost tabHost) {
this.tabHost = tabHost;
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
//界面被选择时调用
tabHost.setCurrentTab(position);
}
@Override
public void onPageScrollStateChanged(int state) {
}
}```
#### Fragment(相同只贴一个)
* Fragment1.java
public class Fragment1 extends Fragment{
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment1,null);
}
}```
- 注意Fragment必须继承自v4包的.
因有多个资源需配置,所以进行简单的封装
- Tab.java
public class Tab {
//标题资源
private int title;
//图片字图案
private int img;
//Fragment类资源
private Class Fragment;
public Tab(int title, int img, Class fragment) {
this.title = title;
this.img = img;
Fragment = fragment;
}
public int getTitle() {
return title;
}
public void setTitle(int title) {
this.title = title;
}
public int getImg() {
return img;
}
public void setImg(int img) {
this.img = img;
}
public Class getFragment() {
return Fragment;
}
public void setFragment(Class fragment) {
Fragment = fragment;
}
}```
#### MainActivity.java
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTabHost;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TabHost;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
public class TabHost_Aty extends AppCompatActivity {
private FragmentTabHost tabHost;
private View view = null;
private LayoutInflater Inflater;
private List list = new ArrayList<>(4);
private ViewPager viewPager;
private List FragmentList = new ArrayList<>(4);
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tabhost);
Inflater = LayoutInflater.from(this);
initTab();
}
//初始化资源
private void initTab() {
tabHost = (FragmentTabHost) findViewById(android.R.id.tabhost);
//绑定Viewpager
tabHost.setup(this,getSupportFragmentManager(),R.id.view_pager);
//添加资源
Tab tabmain = new Tab(R.string.main, R.drawable.btn_notifi, Fragment1.class);
Tab tabcontact = new Tab(R.string.contact, R.drawable.btn_contact, Fragment2.class);
Tab tabmine = new Tab(R.string.setting, R.drawable.btn_mine, Fragment3.class);
Tab tabfound = new Tab(R.string.find, R.drawable.btn_found, Fragment4.class);
list.add(tabmain);
list.add(tabcontact);
list.add(tabmine);
list.add(tabfound);
for (Tab tab : list) {
TabHost.TabSpec spec= tabHost.newTabSpec(getString(tab.getTitle()))//
.setIndicator(getItemView(tab));
tabHost.addTab(spec,tab.getFragment(),null);
}
//清除分界线
tabHost.getTabWidget().setShowDividers(LinearLayout.SHOW_DIVIDER_NONE);
initFragment();
}
/**
* 初始化ViewPager
*/
private void initFragment() {
FragmentList.add(new Fragment1());
FragmentList.add(new Fragment2());
FragmentList.add(new Fragment3());
FragmentList.add(new Fragment4());
viewPager = (ViewPager) findViewById(R.id.view_pager);
//设置适配器
viewPager.setAdapter(new MyAdapter(getSupportFragmentManager(),FragmentList));
//设置界面滑动监听事件
viewPager.addOnPageChangeListener(new MyPageChangeListener(tabHost));
//设置TabHost的点击切换监听事件
tabHost.setOnTabChangedListener(new TabHost.OnTabChangeListener() {
@Override
public void onTabChanged(String tabId) {
int position =tabHost.getCurrentTab();
viewPager.setCurrentItem(position);
}
});
}
//给indicator配置View
private View getItemView(Tab tab) {
view = Inflater.inflate(R.layout.item_view, null);
ImageView img = (ImageView) view.findViewById(R.id.imageview);
TextView textview = (TextView) view.findViewById(R.id.tabtextview);
img.setImageResource(tab.getImg());
textview.setText(tab.getTitle());
return view;
}
}```
效果图:
